From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-2.5 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE, SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 autolearn=no autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 451FFC433E0 for ; Wed, 24 Jun 2020 06:29:14 +0000 (UTC) Received: from merlin.infradead.org (merlin.infradead.org [205.233.59.134]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 1073D20768 for ; Wed, 24 Jun 2020 06:29:13 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="QKUajF2C" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 1073D20768 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=lst.de Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=merlin.20170209; h=Sender:Content-Transfer-Encoding: Content-Type:Cc:List-Subscribe:List-Help:List-Post:List-Archive: List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References:Message-ID: Subject:To:From:Date:Reply-To:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Owner; bh=LEeTucZgFma9f3gs+pfq3UHkMb4Oo4lbZBQY0Dv6NOY=; b=QKUajF2CTJxnlWF5V/LQG9nBU f6YGahXzKQEwUYRcqOxbm1T9vUE8XT6D9fIpEpxQECtVkRaPslMz8DXARCunz/cH52rvoFlrSQWTc GaoeLilHn4DuXQpB9TMDC25YniwrZOsiNpkNl+sf1yWKN8+Ed0uMQ6/niUByoY0Dk0t6s0YcQF/2k CWMvRzTiMPDE8pv3fa71mUAbIUSUbLAm3d+KVJ2basaeB/rHmX9QEHzs+aIx0O+F4bIrkA6ToJQUV 6bbvuiRjwEBkY1NmwdeazzFSXrvPWX6tchPXbT/kJG0/uhHK3Y0hVVOPox43y+JWHUjWj7+w5sL7R iFCsNl4LA==; Received: from localhost ([::1] helo=merlin.infradead.org) by merlin.infradead.org with esmtp (Exim 4.92.3 #3 (Red Hat Linux)) id 1jnyuC-0006VP-6G; Wed, 24 Jun 2020 06:29:08 +0000 Received: from verein.lst.de ([213.95.11.211]) by merlin.infradead.org with esmtps (Exim 4.92.3 #3 (Red Hat Linux)) id 1jnyu8-0006Uf-O2 for linux-nvme@lists.infradead.org; Wed, 24 Jun 2020 06:29:05 +0000 Received: by verein.lst.de (Postfix, from userid 2407) id 335AE68AEF; Wed, 24 Jun 2020 08:29:02 +0200 (CEST) Date: Wed, 24 Jun 2020 08:29:02 +0200 From: Christoph Hellwig To: Sagi Grimberg Subject: Re: [PATCH v2 for-5.8-rc 1/6] nvme: fix possible deadlock when I/O is blocked Message-ID: <20200624062902.GA17594@lst.de> References: <20200624001853.5408-1-sagi@grimberg.me> <20200624001853.5408-2-sagi@grimberg.me> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20200624001853.5408-2-sagi@grimberg.me> User-Agent: Mutt/1.5.17 (2007-11-01) X-BeenThere: linux-nvme@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Keith Busch , Anton Eidelman , Christoph Hellwig , linux-nvme@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "Linux-nvme" Errors-To: linux-nvme-bounces+linux-nvme=archiver.kernel.org@lists.infradead.org On Tue, Jun 23, 2020 at 05:18:48PM -0700, Sagi Grimberg wrote: > Revert fab7772bfbcf ("nvme-multipath: revalidate nvme_ns_head gendisk > in nvme_validate_ns") > > When adding a new namespace to the head disk (via nvme_mpath_set_live) > we will see partition scan which triggers I/O on the mpath device node. > This process will usually be triggered from the scan_work which holds > the scan_lock. If I/O blocks (if we got ana change currently have only > available paths but none are accessible) this can deadlock on the head > disk bd_mutex as both partition scan I/O takes it, and head disk revalidation > takes it to check for resize (also triggered from scan_work on a different > path). See trace [1]. > > This is no longer needed since commit cb224c3af4df ("nvme: Convert to > use set_capacity_revalidate_and_notify") which already updates resize > info without unnecessarily revalidating the disk. Did you look if any other revalidation gets skipped this way? E.g. LBA size change? >From purely the size POV this looks good, though. _______________________________________________ Linux-nvme mailing list Linux-nvme@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-nvme